This section provides background information related to the present disclosure which is not necessarily prior art.
Corner assemblies for suspension systems are well known in the motor vehicle industry. The most common form of a corner assembly for a suspension is the strut suspension system. The strut system includes a coil spring located concentrically around a telescopic strut which is the shock absorber. The upper end of the strut assembly includes an upper mounting assembly which is mounted in a tower formed by the vehicle body at a position above the wheel arch of the vehicle. The lower end of the strut assembly is attached to a knuckle of the wheel assembly. Typically the knuckle includes a clamping mechanism which clamps the outer tube of the shock absorber.
The coil spring is located around the shock absorber and it extends between an upper spring seat which is a part of the top mount assembly for the strut assembly and a lower spring seat which is attached, typically by welding, to the shock absorber of the strut assembly. The outer tube of the shock absorber must be designed strong enough to meet the clamping load requirements for interfacing with the vehicle's knuckle. While the clamped area of the outer tube that interfaces with the knuckle must be designed to withstand the clamping load requirements, the remainder of the outer tube or unclamped area does not have these strength requirements. The strength requirements for the non-clamped area of the outer tube are typically lower than the strength requirements of the clamped portion. Typically, the outer tube of the shock absorber is designed as a constant wall thickness tube. The thickness of the outer tube is designed to meet the clamping load requirements and because the non-clamped portion of the shock absorber does not require the same strength as the clamped portion, the constant wall thickness tube is over designed in the non-clamped portion. This leads to wasted material and excessive costs. While a single piece tube having a variable thickness could be applied to this application, the costs and complications in manufacturing a single piece variable wall thickness tube does not make this an acceptable option.
Other types of corner assemblies include a strut assembly which includes a yoke where the outer tube of the shock absorber is clamped by the yoke which is attached to a lower control arm, a knuckle or another component of the corner assembly. Another type of corner assembly is a dual control arm corner assembly which includes a yoke where the outer tube of the shock absorber is clamped by the yoke which is attached to a lower control arm, a knuckle or another component of the corner assembly. In each of these corner assemblies, the shock absorber is attached to the sprung mass of the vehicle. These corner assemblies have the same issue with regard to the clamping of the outer tube of the shock absorber discussed above for the strut assembly.